package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWoker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {


    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWoker redisIdWoker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Autowired
    private RedissonClient redissionClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }


    //创建线程池
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    @PostConstruct
    public void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }
    String queueName="stream.orders";
    private class VoucherOrderHandler implements Runnable {

        @Override
        public void run() {
            while (true) {
                try {
                    //获取消息队列中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS streams.order >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())

                    );
                    //判断消息获取是否成功
                    if(list==null||list.isEmpty()){
                        //失败，则没有消息，继续下一次循环
                        continue;
                    }
                    //解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //成功，可以下单
                    handleVoucherOrder(voucherOrder);
                    //ACK确认 SACK stream.orders g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                    Thread.sleep(6000 * 1000);
                } catch (Exception e) {
                    log.error("处理订单异常", e);

                    handlePendingList();
                }
            }
        }
    }

    private void handlePendingList() {
        while (true) {
            try {
                //获取pendingList中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 STREAMS streams.order 0
                List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                        Consumer.from("g1", "c1"),
                        StreamReadOptions.empty().count(1),
                        StreamOffset.create(queueName, ReadOffset.from("0"))

                );
                //判断消息获取是否成功
                if(list==null||list.isEmpty()){
                    //失败，则pendingList没有消息，结束循环
                    break;
                }
                //解析消息中的订单信息
                MapRecord<String, Object, Object> record = list.get(0);
                Map<Object, Object> values = record.getValue();
                VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                //成功，可以下单
                handleVoucherOrder(voucherOrder);
                //ACK确认 SACK stream.orders g1 id
                stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                Thread.sleep(6000 * 1000);
            } catch (Exception e) {
                log.error("处理pendingList异常", e);
                try {
                    Thread.sleep(6000*1000);
                } catch (InterruptedException ex) {
                    ex.printStackTrace();
                }
            }
        }
    }
    /*
    //创建阻塞队列
    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
    //线程任务
    private class VoucherOrderHandler implements Runnable {

        @Override
        public void run() {
            while (true) {
                try {
                    //获取队列中的订单信息
                    VoucherOrder voucherOrder = orderTasks.take();
                    //创建订单
                    handleVoucherOrder(voucherOrder);
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                }
            }
        }
    }

     */

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //获取用户
        Long userId = voucherOrder.getUserId();
        //创建锁对象
        RLock lock = redissionClient.getLock("lock:order:" + userId);
        //尝试获取锁
        boolean isLock = lock.tryLock();
        //判断是否成功
        if (!isLock) {
            //获取锁失败，返回错误信息
            log.error("不允许重复下单");
            return;

        }
        //成功，则执行以下业务
        try {

            proxy.createVoucherOrder(voucherOrder);
        } finally {
            //最后要释放锁
            lock.unlock();
        }


    }

    private IVoucherOrderService proxy;
    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户信息
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        long orderId = redisIdWoker.nextId("order");
        //执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString(),
                String.valueOf(orderId)
        );
        int r = result.intValue();
        //判断结果是否为0
        if (r != 0) {
            //不为0，没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单喵~");
        }

        //获取代理对象
        proxy=(IVoucherOrderService) AopContext.currentProxy();
        //返回订单id
        return Result.ok(orderId);
    }
    /*
    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户信息
        Long userId = UserHolder.getUser().getId();
        //执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString()
        );
        int r = result.intValue();
        //判断结果是否为0
        if (r != 0) {
            //不为0，没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单喵~");
        }


        //为0，有购买资格，把下单信息保存到阻塞队列中
        long orderId = redisIdWoker.nextId("order");
        //把下单信息保存到阻塞队列中
        VoucherOrder voucherOrder = new VoucherOrder();
        //订单id
        voucherOrder.setId(orderId);
        //用户id
        voucherOrder.setUserId(userId);
        //代金券id
        voucherOrder.setVoucherId(voucherId);
        //放入阻塞队列
        orderTasks.add(voucherOrder);
        //获取代理对象
        proxy=(IVoucherOrderService) AopContext.currentProxy();
        //返回订单id
        return Result.ok(orderId);
    }

     */
   /* @Override
    public Result seckillVoucher(Long voucherId) {
        //查询优惠券
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        //判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
            //尚未开始
            return Result.fail("秒杀尚未开始");
        }
        //判断秒杀是否结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            //已经结束
            return Result.fail("秒杀已经结束");
        }
        //判断库存是否充足
        if (voucher.getStock()<1) {
            //库存不足
            return Result.fail("库存不足");
        }
        Long userId = UserHolder.getUser().getId();
        //创建锁对象
        //SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        RLock lock = redissionClient.getLock("lock:order:" + userId);
        //尝试获取锁
        boolean isLock = lock.tryLock();
        //判断是否成功
        if(!isLock){
            //获取锁失败，返回错误信息
            return Result.fail("不允许重复下单");

        }
        //成功，则执行以下业务
        try{
            //获取代理对象(事务)
            IVoucherOrderService proxy =(IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        }
        finally {
            //最后要释放锁
            lock.unlock();
        }


    }
    */

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单
        Long userId = voucherOrder.getUserId();


        //1.查询订单
        Integer count = query().eq("user_id", userId)
                .eq("voucher_id", voucherOrder.getVoucherId())
                .count();
        //2.判断是否存在
        if (count > 0) {
            log.info("<用户已经购买过一次>");
            return ;
        }
        //扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock=stock-1")
                .eq("voucher_id", voucherOrder.getVoucherId())
                .gt("stock", 0)//where stock > 0
                .update();
        if (!success) {
            //扣减失败
            log.error("库存不足");
            return;
        }
        //创建订单
        save(voucherOrder);


    }
}

